Process of treating slags.



UNITED STATES PATENT OFFICE.

WSSES A. GABBED, OI EIIKH'UIBT, NEW YORK.

No Drawing.

To all whom it may concern:

Be it known that I, ULYSSES A. Gannon, -a citizen of the United States, residin at Elrnhurst, in the county of Queens and tate of New York, have invented certain newand useful Improvements in Processes of Treatin Slag, of which the following is a 5 col cation.

of cement,,being as a rule free from iron,

or containing it in such negii 'ble quantities as not to make the same 0 jectionable.

On the other hand, slag from co per-smelting furnaces, thatjsto' say, maces in which theroasted ore issmelted for parposes of'making matte, contains alarge percentage of iron in the form of ferrous oxid in combination with silica (silicate of iron) whichmakesthe slag objectionable and entirely unsuitable for the manufacture of cement. Thousands of tons of this slag go to waste every year any'commerc'ial or industrial purpose. i. The

because unavailable for ob ect of my invention is to remove the objectionable iron (and other bases) from such slag, thereby producing a slag that is 'com arativelytgure, and free from discoloring uses, at e same time recovering the iron for independent use. The advantages of my invention will be fully apparent from a detailed description thereof which is as follows: 7

The slag istapped from the sm'eltingfur- 'nace and run Into a suitable crucible, slagpot, converter; or equivalent treatment vessel in, which the o erations under my procase may be car'ri on, The charge of 51 in the treatment vessel should be maintainzd in a highly heated and fluid condition, this being accomplished by burning within the mass a proper-complement of carbonaceous fuel, referabl powdered coal, introduced into tliebath y a current or at of airor other'surter of combustionb own into the body of t e charge at a point below the surfacethereof. This is best accomplished by providing the vessel with suitable et nozzles or twyers dischargingthrough the bottom of the vessel directly into the bath, saidnozzles or twyers being connected by pipes with any suitable source of air supply, proper provision bein made for mixing the powdered fuel with the air before'the latter reaches the jet nozzles or twyers aforespeciiilldtion of Letters Patent. Application filed June c, 1010. semi Ho. seam.

alent, to furnish a suitable Patented Oct. 21, 1919.

the body of the char e, thereb maintaining the bath in a highly uid con ition and pre venting the same from becoming viscous. The powdered fuel should be intrmiuced in quantities suflicient to not only keep the 1;

bath vll' fluid condition but to reduce the iron oxid combined with the'silica of the slag; and in practice this excess carbon may preferably be introduced in the later stages of the process, or what may be termed the eeoondstage after the desired fluidity and tiger-attire has been attained by the int notion. of'the first portions of the fuel. The bath having reached'the desired temperature, the b ment is continued, a suitable quantity of lime referabl in powdered or granular form eing ad ed. The lime, thou h preferably blown into the bath with t e powdered coal maybe charged into the vessel independently, the object sought being to cause the coal as well as the lune to thoroughly ermeate and become diffused throughout he bath. The diffused carbon operates to reduce theiiron of the sla the lime replacing the iron thus reduce In other words, there is produced a lime slag or a silicate of calcium, and iron in the metallic state. The iron drops to the bottom and may be conveniently removed while the slag is still liquid, b pouring oil the slag. When we'consider t at these co per slugs often contain all the way from 3 to 45 per cent. of. iron which goes to waste, the'desirability of recovering this iron by some simgle process at once becomes apparent. By

lowing chargie of copper slag in conjune tion with a su cient .(fluantity of carbons ceou's fuel to keep the ag'in a highly fi'uid ation with carbon in excess. to reduce the iron,"in the resence of a. fluxing maternal such as lime carbonate or oxid or its equiw use for the silica originally combined with the iron (lthe lime having a ateraiiinity for silica is an hasiron and once replacing the latter under proper conditions),- I not only; recover in practically one operation the iron, but at the same time produce a sla (calcium silicate) suitable for the manu mature of cement. There must be of course a guflieat with its fuel complecient amount of carbonaceous fuel or coal present at all times to nuiintuin the both In a fluid condition, the excess carbon being depended upon to nctras the reducing agent for the iron; amlwhile I have mentioned lime as the fluxing agent, it is to he understood that so for us the invention is concerned any equivalent flexing material may -be substituted for the lime, as for example magnesia or a mixture of the carbonates of ma iesium and calcium. If the object sought be the mere recovery of the iron then anysuitable fluxing materiel might be employed. If the prlmary obgect b the production of a slag suitable for the manufacture of cement, then lime is the preferred flexing agent since a lime slag is best suited for that purpose.

It is apparent from the foregoing that the quantities of the reagents added to the both of molten slag undergoing treatment will vary with the charge operated on. The skilled metullurgist will be governed by conditions. The quantity of excess fuel added for purposes of reducing the iron will depend on the percentage of iron in the slag, a matter which can be readily arrived at by suitable tests. The quantity of fluxing material added in the reducing stages of the process will likewise depend on the percentage of iron, sullice it to say however that enough lime or its equivalent should be :idded to take up the silica released by the ron. v

The instrumentalities by which the recess can be carried on may be varied, and in the majority of cases may be very simple. For exampl we may employ an ordiv nary slag pot mounted on trunnions into which the slag from the copper smelting furnace is tapped, equipping the pot with an air pipe entering the bottom of the pot. Into this pipe a certain quantity of pow dered fuel is introduced, said fuel being carried along by the air forced through the pipe, the mixture of air and fuel rising up,

through the molten mass, certain portions of the coal being burned and other portions reducing the iron when the proper conditions of tempertiture and fluidity have been attained, it being-understtmd of course that at the rcducing stagi proper, a proper coinlemcnt of lime or its equivalent is either introduced into the air pipe to be blown into the bath in conjunction with the fuel, or charged indtmendently into the pot to take up the silica. serve asan cxmuple: other forms may be readily devised by the skilled metullurgist. The air introduced into the molten slag may of course be at normal tenunernture or it hot blast may be utilized. in this regard I am not to be restricted. Neithennm I to he restricted to the precise chnntcter of fuel or heating and reducing agent employed, it he take up the silica released by the iron.

The above apparatus will.

ing slllllcicnl; to state that the fuel should he preferably carlmnuceous and in fluent form, not excluding liquid and gaseous fuel, The reagents should of course be introduced into the body or mass of the molten slag below the surface thereof so as to permeate every portion of the bath and insure a complete chemical reuction between the slag and said reagents. Obviously, the process is not to be restricted in its application to what are technically termed slugs but may he'cmployed for treating any equivalent material or silicates from which the metal component can be extracted.

Having described my invention what I claim is:

1. In the treatment of slugs carrying iron, the process which consists in subjecting a charge of molten slag to the action of a blast of a supporter of combustion, and a, reducing agent-in a finely divided state permeating said charge, and continuing the operation with a sufficient excess of reducing agent to reduce the iron of the slug.

2. In the treatment of slags carrying iron, the process which consists in subjecting a charge of molten slag to the action of a. blast of air directed into the body of the charge below the surface thereof, and a carbonaceous reducing agent in a finely divided state permeating said charge, and continuing the operation with a sufficient excess of reducing reagent in the presence of a fluxing material-added to the charge to 3. In the treatment of slags carrying iron,

the process which consists in subjecting a charge of molten slag to the action of a blast of air charged with powdered carbonaceous fuel directed into the bath of slag below the surface thereof, continuing'thc blowing operation with an excess of fuel in theprcsenw of suitable fluxing material permeating the bath, whereby the iron is reduced and a slug free from iron is formed.

4. In the treatment of slugs from copper smelting furnaces, the process which con sists in subjecting a bath of molten slag in a treatment vessel to the action of a blast of air mixed with powdered coal directed into the mass of the slag below the surface thereof to raise the temperature of the bath, continuing the blowing operation with a Hllfllfillllll' excess of the powdered cool to reduce the iron, and with a. suitable comple- 1 0 ment of lime in a finely divided state to operate as a flux and take up the silica released by the iron, tl'iereby producing metalliciron and n silicate of calcium.

5. In the treatment of slugs from copper snu-lting furnaces, the process which consists in placing a churn: of molten slug into a treatment vessel, directing jets of air carrying! powdered eon] into the body of the slaghelow the surface thereof to raise the 0 Visioning an, em; powdered ml to the end the same time charging thegeir streem'with a. proper comrial to form a, lime slag.

7. In the treatment of carrying iron, the 'n'ocese of subjecting a eharge'of molten sin to the action of a, blast of air carrying fine ltoerbonaceous reduoing reagent, then tiling the.

continuing the blowing operation with the addition to the 'ii r stream of lime in a. finely divided state as a fiuxing agent, whereby the iron is reduced and a. lime slag formed.

8. In the treatment of slugs carrying iron, the process which eonsists in subjecting a, charge of moiten'slag below the surface thereof to the action of a blast of a, supporter of combustion, and a fluent reducing agent permeating said charge, and continuin the operation with a s'uifieient excess of re ucing agent to reduce the iron of the slag.

In testimony whereof I afiix my signature, in presence of two witnesses.

. ULYSSES A. GARRED.

Witnesses:

HENRY PAUL, G. U. MUNsoN. 

